The present invention generally relates to railroad hopper cars and, more specifically, to a gate assembly which is attachable to a body of a railroad hopper car to selectively control the discharge of ballast in the railroad hopper car to a railbed below. A method for operating the gate assembly is also disclosed.
Gate assemblies allowing for unloading of ballast from railroad hopper cars are well known in the art. Such gate assemblies are typically arranged to opposite sides of the longitudinal centerline of the railroad hopper car and lengthwise along a bottom of the hopper car. Moreover, it is common to design each gate assembly such that ballast can be selectively distributed from the railcar to one or the other or both sides of the rails along which the railcar travels. In this regard, a frame of each gate assembly defines inner and outer outlets from which ballast can be discharged from the hopper car. The gate assembly furthermore includes door assemblies arranged in operable combination with the outlets to selectively control the discharge of ballast from the hopper car as a function of the disposition of the door assembly relative to the respective outlet.
Some such gate assemblies employ manually actuated door opening and closing devices. That is, by manually rotating a handle, as with an elongated steel bar or the like, and through a linkage, each door assembly is moved between open and closed positions. Thus, a control opening on each side of the gate assembly and through which the ballast is discharged must be set by hand when the train is stationary. Alternatively, operators, on each side of the railcar, and for each door assembly, initially set the control opening and then move down the track at the speed at which the railcar moves to maintain control over the discharge of ballast from the railroad hopper car.
To reduce numerous problems associated with manually controlling the disposition of the doors of such gate assemblies, some gate assemblies have been designed with powered drivers for controlling the disposition of the door assemblies relative to the outlets in the frame of the gate assembly. For example, some gate assemblies have been designed with hydraulic drivers disposed between the gate assembly frame and each door assembly for positioning the door assemblies relative to the frame thereby controlling the discharge of ballast from the hopper car. As will be appreciated, the railroad cars equipped with these gate assemblies operate in various temperature climates. Unfortunately, extremely cold conditions have an adverse effect on and often prohibit the use of hydraulic drivers for such gate assemblies.
Hydraulically operated gate assemblies are furthermore hindered by the relatively high maintenance required for the hydraulic drivers of such gates. Moreover, and as will be appreciated by those skilled in the art, such hydraulic drivers are not easily repaired. Inadvertent or other forms of contamination of the hydraulic fluids associated with these types of drivers is also a paramount concern. Additionally, and especially when used in conjunction with gate assemblies, hydraulically operated drivers normally consume more power than other types of drivers primarily due to the frictional operating characteristics inherent with such drivers. Hydraulically operated gate assemblies furthermore present serious environmental concerns during maintenance and throughout the life span of the drivers.
Gate assemblies utilizing pressurized air operated drivers are likewise susceptible to failure. An unavoidable accumulation of moisture in the reservoirs and accumulators of air operated gates tends to quickly freeze valves typically arranged in operable combination therewith. Of course, when the valves freeze, such gate assemblies are rendered substantially inoperable until the valves are sufficiently thawed to allow for operation of the air operated system. This can cause a significant delay. Of course, such delays are both costly and cannot always be tolerated.
Another problem which has been identified with air operated systems involves the size or diameter of the cylinders which are required to develop the necessary force or power required to move the gates from a closed position toward an open position when a full load or weight of the ballast is applied against the gates. Of course, diminishing the diameter or width of the drivers and thereby yielding more spaciousness in the area of the gates is a continuing and long sought goal of railroad hopper car gate designers for such spaciousness can alternatively and advantageously be used for alternative purposes. Like hydraulically operated systems, air operated systems are not easily repaired. Moreover, the hoses or conduits extending from the air cylinders, ultimately, have to be connected to the locomotives, thus, adding to the overall costs of such systems.
Electric drivers for such railroad hopper car gate assemblies typically suffer from several drawbacks. First, known electric drivers have neither the speed nor power to allow the door assemblies to be moved from a closed position toward an open position without placing an extremely heavy draw on the power source. Second, lengthy electrical conduits are required between the door assemblies on those railcars at the rear of the train consist and the locomotive or an alternative source of power for such electrical drivers. Moreover, component parts of such electric motors are susceptible to shocks and vibrations of the railcar as the car is transported between locations across the country.
Often times, railroad cars having electrically operated gates are equipped such that the electric motors on such gates can be operated either through switches on the railcar or through use of a remote control apparatus. Research has found that when one operator or maintenance person is manually controlling the electrically operated gate in a certain direction, as through a switch on the side of the car, another operator or maintenance person, with the remote control apparatus, and although inadvertent, often signals or directs the same electrically driven gate to operate in an opposite or reverse direction, thus, causing significant problems. As will be appreciated, directing or controlling the same electric driver for a gate assembly from two opposite sources but in opposite directions can cause significant problems typically resulting in damage to the electric motor.
Thus, there is a continuing need and desire for a railroad hopper car gate assembly which uses other than manually operated door assemblies so as to promote remote or automatic actuation of the gate assembly in an efficient and effective manner without having each railroad car equipped with such a door assembly having to be connected to a common power source and which is operable through all temperatures ranges. Furthermore, there is a continuing need and desire to protect the electric drivers for such door assemblies against concurrent and inadvertent control directives derived from two sources and which are in opposition relative to each other.
In view of the above, and in accordance with one aspect of the present invention, there is provided a railroad hopper car gate assembly including a frame configured for attachment to a hopper body of a railroad hopper car in material receiving relation relative to an outlet on the railroad car, and wherein the frame defines at least one discharge opening. A door assembly is mounted on the frame for generally vertical sliding movements between open and closed positions relative to the discharge opening on said frame. One salient feature of the present invention relates to providing a driver which is operably coupled between the frame and the door assembly for selectively effecting sliding movements of the door assembly relative to said discharge opening between the open and closed positions.
To overcome problems of heretofore known drivers for such railroad hopper car gate assemblies, the driver of the present invention is specifically designed to develop up to a 2000 lb. opening force on the door assembly and a substantially constant speed of about 2.0 inches per second as the door assembly moves from the closed position to the open position. Preferably, each driver for the gate assembly includes a direct current electric drive motor which draws less than about 30 amperes from a power source when the door assembly is moved from the closed position to the open position.
Preferably, the frame of the railroad hopper car gate assembly of the present invention defines inner and outer discharge openings; with each opening having a door assembly arranged in operable association therewith and wherein each door assembly is operated by a driver. Each discharge opening on the frame is disposed to one or the other side of a rail over which the railcar moves. The frame of the gate assembly furthermore preferably includes a pair of opposed angular ledges disposed to opposed sides of each discharge opening in generally planar relation relative to each other for supporting opposite sides of the door assembly for generally vertical sliding movements between the open and closed positions relative to the respective discharge opening on said frame. Each door assembly includes a door having a generally planar configuration including upper and lower surfaces and further includes slides arranged along a portion of the lower surface of the door. The door slides engage with the ledges on the frame and dispose the door assembly at an acute angle relative to the ledges on the frame.
In a preferred embodiment, the gate assembly includes a 24 volt power source preferably in the form of batteries arranged and carried on each railroad hopper car. Moreover, a solar array provided on each railroad hopper car equipped with a gate assembly according to the present invention is connected to and serves to maintain the batteries in a constant charge. In those preferred designs where batteries are used as a power source, an electrical connector extends between the batteries and the direct current motor of the driver. Such electrical connector is advantageously provided with a first releasable connector at that end where the electrical connector is operably coupled to the driver and a second releasable connector at that end whereat the connector is operably connected to the batteries thereby facilitating repair and/or replacement of either the driver or the batteries as required or needed.
Each driver is preferably designed with a reversible electromechanical motor. To inhibit inadvertent damage to the direct current electric motor of each modular driver, a thermal overload apparatus is preferably arranged as part of each driver. Moreover, and to inhibit damage to the driver from limitations on sliding movements of a respective door assembly, each driver is preferably provided with a clutch which inhibits transfer of power to an output of the driver under predetermined conditions.
Each electromechanical driver is designed to be substantially vibration resistant. In a preferred form, the electromechanical driver includes a gear set driven by the direct current electric motor. The gear set preferably includes a driven gear for driving a worm gear coupled to an output of the driver. In a preferred embodiment, each driver furthermore includes a first housing connected to the motor and arranged in surrounding relation relative to the gear set and a second housing connected to the first housing and arranged in surrounding relation relative to the worm gear. Seal structure, disposed between the second housing and the output of the driver, allows each driver to be angularly disposed relative to the frame of the gate assembly as required and/or needed. In a preferred embodiment, the drivers are disposed in substantially common vertical planes relative to each other thereby substantially reducing the overall width of the gate assembly.
In a preferred embodiment, a linkage mechanism operably couples each driver to a respective door assembly. In one embodiment, the gate assembly further includes inner and outer shafts. The inner shaft is rotatably supported by the gate assembly frame and is disposed to an inner side of a longitudinal axis defined by the frame and the outer shaft is rotatably supported by the frame and is disposed to an outer side of the longitudinal axis defined by the gate assembly frame. The linkage assembly operably couples each shaft with a respective gate. With the present invention, each shaft turns through an arc of approximately 70xc2x0 as the respective gate moved thereby moves between the open and the closed positions.
In a preferred form, the reversible driver for each door assembly can be operated either through a manual actuator or switch mounted on the railroad hopper car or via a radio frequency transmitter or other suitable apparatus capable of remotely actuating the door assemblies. As such, the size of each opening through which ballast can be discharged from the hopper car can be controlled either through manual manipulation of the actuator or switch, as an operator walks along adjacent the railcar, or from a remote location via the radio transmitter. As noted above, however, the operator using the remote control apparatus may not always be positioned to determine or accurately observe that an operator, possibly walking on an opposite side of the car, may be using the switch or manual actuator in a manner which may be contrary to or the reverse of the manner in which the remote control actuator is being operated. Accordingly, two directives or signals, opposite from one another, can be inadvertently and concurrently sent to the electric drivers to control the gate assemblies. As mentioned above, and as will be appreciated by those skilled in the art, sending two opposed signals directing a single electric motor to operate in reverse directions can prove detrimental to proper performance of the driver and can even result in significant damage thereto.
According to another aspect of the invention, the switches or manual actuators on the car and the remote control apparatus for operating the drivers of the door assemblies are operably connected to a controller including a computerized microprocessing unit operable in combination with the 24 volt system mounted on each railcar. The microprocessing unit includes circuitry for inhibiting damage to the reversible drivers when two opposing open/close directives are concurrently developed or derived from the manual actuators and the remote control apparatus.
According to still another aspect of the invention, a method for operating the gate assemblies including the step of inhibiting damage to the reversible drivers when two opposing open/close directives are concurrently developed or derived from the manual actuators and the remote control apparatus is also disclosed.
A principal object of this invention is to provide a gate assembly for a railroad hopper car including a slidable door assembly whose selectively controlled position allows ballast from a hopper car to be discharged to one or the other or both sides of a rail over which the railcar moves and which includes electromechanical drivers for moving the door assemblies, with each such electromechanical driver having sufficient speed and power to selectively permit opening of the door assembly while the door assembly is under full load through use of a direct current electric motor which draws no more than 30 amperes from an electrical power source to effect movement of the gate from the closed position to the open position.
Another object of this invention is to provide a gate assembly for a railroad hopper car wherein each door assembly is operably coupled to electromechanical drivers which are modular in design thereby readily permitting their repair and/or replacement, as needed and/or desired, and which are operated from a 24 volt system including batteries which are mounted on the railroad hopper car.
Still a further object of this invention is to provide a gate assembly for a railroad hopper car wherein each door assembly is operably coupled to an electromechanical driver including a direct current electric motor having multiple housings which are both shock and vibration resistant thereby promoting transportation of the railcar between locations.
Another object of this invention is to provide a gate assembly for a railroad hopper car wherein the each door assembly is operably coupled to an electromechanical driver including a direct current electric motor that is sealed to the environment and allows the drivers to be orientated in substantially all directions relative to the frame.
Still another object of the present invention is to design a gate assembly for allowing ballast to be discharged to either or both sides of a rail along which a railcar moves and which has a reduced width requirement when matched to comparable and heretofore known gates.
A further object of this invention is to allow the drivers for each door assembly to be operated either through manual manipulation of an actuator on the railcar or through a remote control apparatus, and wherein each driver is protected against damage resulting from opposing open/close directives being concurrently developed by the manual actuators and the remote control apparatus and which are intended to control the same door assembly.
Yet another object of this invention is to provide a method wherein the door assemblies of the gate assembly are selectively controlled as through manual manipulation of switches or through a remote control apparatus and wherein the drivers for each gate assembly are inhibited from damage resulting from opposing open/close directives being concurrently directed toward a single driver from both the manual actuators and the remote control apparatus.
These and other objects, aims and advantages of the present invention will become readily apparent from the following detailed description, the drawings, and the appended claims.